It's one of the most feared volcanoes, so we're closely monitoring it, Einarsson told Associated Press.
It's normal for earthquakes to be detected around Katla. What's a bit unusual is that we're seeing swarms of small earthquakes, some occurring every 10 minutes or so, he said.
Katla is located in the southernmost glacier in Iceland. It is situated to the east of the Eyjafjallajökull, where an eruption in 2010 caused vast destructions.
The increase in seismic activity follows a series of small earthquakes which struck along the Mid-Atlantic Ridge on Monday.
The quakes, ranging between 4 and 5 magnitude, occurred on the part of the Mid-Atlantic Ridge that rises up to the ocean surface to the southwest of Iceland, says Irish Weather Online.
A 4.9 magnitude earthquake which hit at 06:05:37 GMT on Monday was the strongest quake and it was located 727 km southwest of the Icelandic capital Reykjavík.
According to the European-Mediterranean Seismological Centre, the strongest quake was followed by three 4.6 magnitude tremors and one 4.8 tremor.
Katla was last erupted in 1918. Katla also threatens Iceland of disastrous flooding if its ice cap melts. It usually erupts every 80 years or so.
The seismic activity in the surrounding area around Katla started to increase in July but has since grown even stronger.
Even volcano has a different personality like humans, Einarsson said.
We look at the behavior, try to analyze patterns and then try to come up with an explanation, Einarsson said. This is a bit difficult to interpret so far, but it's correct to say that it signals some sort of activity in the volcano and some sort of magna intrusions are probably taking place.
Geologists are also concerned about another volcano in Iceland, known as Hekla volcano, which is not covered by a glacier and it produces little seismic activity.
Hekla volcano was also known as the Gateway to Hell during the Middle Ages and Icelanders called it the country's most active volcano.
If we saw earthquakes like this in Hekla, we would immediately signal a warning sign, Einarsson said.
A mid-ocean ridge actually rises above sea level in Island and many small volcano eruptions along the ocean basin are not detected because they are not seen easily.